U.S. patent number 5,644,345 [Application Number 08/329,164] was granted by the patent office on 1997-07-01 for service station for ink jet printer.
This patent grant is currently assigned to Olivetti-Canon Industriale S.p.A.. Invention is credited to Antonio Toniolo.
United States Patent |
5,644,345 |
Toniolo |
July 1, 1997 |
Service station for ink jet printer
Abstract
In a station for cleaning, restoring and protecting the nozzles
of an ink jet printer, a cleaning blade is connected to the nozzle
restoring and protecting device and controlled by it when moved by
the motion of the print head into its operating position. The
restoring and protecting device comprises two covers that are
selectively coupled to one or the other of two heads for printing
in black or in color, respectively. The restoring and protecting
device sets the cleaning blade in the best position for cleaning
the two heads, by means of a rocker. The service station is of a
simple construction and uses a small number of component parts.
Inventors: |
Toniolo; Antonio (Aglie',
IT) |
Assignee: |
Olivetti-Canon Industriale
S.p.A. (Ivrea, IT)
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Family
ID: |
11411874 |
Appl.
No.: |
08/329,164 |
Filed: |
October 26, 1994 |
Foreign Application Priority Data
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Nov 11, 1993 [IT] |
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TO93A0854 |
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Current U.S.
Class: |
347/32;
347/33 |
Current CPC
Class: |
B41J
2/16547 (20130101); B41J 2002/1742 (20130101) |
Current International
Class: |
B41J
2/165 (20060101); B41J 002/165 () |
Field of
Search: |
;347/32,29,30,33 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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410691 |
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Jan 1991 |
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EP |
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465260 |
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Jan 1992 |
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EP |
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Primary Examiner: Barlow, Jr.; John E.
Attorney, Agent or Firm: Banner & Witcoff, Ltd.
Claims
What it is claimed is:
1. A service station for an ink jet printer, said printer including
a printing support; a carriage that moves with respect to said
printing support; and a print head of a first kind carried by said
carriage, said print head having a plurality of nozzles for
expelling drops of ink, said service station comprising:
cleaning means for cleaning said print head on said carriage when
said carriage is moved to said service station, said cleaning means
including a flexible blade that slides over said print head to
remove residues of ink thereon, said blade being movable from a
position of interference with said print head to an inactive
position spaced away from said print head;
nozzle restoring and protecting means for restoring and protecting
said nozzles of said print head when said carriage is located at
said service station, said restoring and protecting means including
a support, said support including ink collecting means for
collecting the ink purged from said nozzles and supporting a cover
for protecting said nozzles, said support being independently
pivotable around and linearly movable along a shaft perpendicular
to the motion of said print head from a rest position, in which
said cover is away from said print head, to an operating position,
in which said cover is in contact with said print head;
means engageable by a trigger member on said carriage during its
movement towards said service station for pivoting said support
from said rest position to said operating position, said support
being connected to said blade by means of a rocker so as to move
said blade to said inactive position spaced away from said print
head simultaneously to the movement of said support to said
operating position to bring said cover against said print head.
2. The service station as claimed in claim 1, in which said ink
collecting means is provided with a hole of elongate section
through which said shaft passes, to allow said ink collecting means
to move with respect to said support.
3. The service station as claimed in claim 1, in which said cover
is mounted on said ink collecting means.
4. The service station as claimed in claim 1, in which said print
head of a first kind is replaceable by another print head of a
second kind different from said first kind.
5. The service station as claimed in claim 4, in which said ink
collecting means comprises first and second recesses, said first of
said recesses collecting ink from the nozzles of said print head of
said first kind, and said second of said recesses collecting ink
from said other print head of said second kind.
6. A service station for an ink jet printer, said printer being
capable of taking selectively a first print head of a first kind
and a second print head of a second kind different from said first
kind, said first print head and said second print head having a
plurality of ink expelling nozzles; said service station
comprising:
a nozzle restoring, protecting and cleaning device including a
cleaning member for cleaning said nozzles, and ink collecting means
selectively coupled to said first print head and to said second
print head for collecting the ink purged from said nozzles, said
ink collecting means including a support movable linearly between
first and second coupling positions to couple selectively
respectively with said first print head and with said second print
head, said support being rotatable between a rest position and an
operating position in each of said coupling positions;
setting means controlled by said ink collecting means for setting
said cleaning member in a respective location adapted to a selected
one of said first print head and of said second print head; wherein
said setting means comprises a rocker pivotable about an axis and
having a first arm connected to said cleaning member and a second
arm running parallel with said axis and connected rotatably and
slidingly to a fork fixed to said ink collecting means.
7. The service station as claimed in claim 6, in which said second
arm comprises a guide engaged in said fork, said guide comprising
two endmost portions extending parallel with said axis and engaged
selectively in said fork when said ink collecting means are coupled
to said first print head and to said second print head, and a third
intermediate part inclined relative to said axis and engaged by
said fork while said ink collecting means are moving from said
first of said coupling positions to said second of said coupling
positions.
8. An ink jet printer capable of taking selectively a first print
head of a first kind and a second print head of a second kind
different from said first kind, said print heads having nozzles for
expelling drops of ink, said printer comprising:
a nozzle restoring, protecting and cleaning device including a
cleaning member for cleaning said nozzles; and ink collecting means
selectively couplable to said first print head and to said second
print head for collecting the ink purged from said nozzles; said
ink collecting means comprising a support movable linearly between
first and second coupling positions to couple selectively
respectively with said first print head and with said second print
head, said support being rotatable between a rest position and an
operating position in each of said coupling positions
setting means controlled by said ink collecting means for setting
said cleaning member in a respective location selectively adapted
to said first print head and to said second print head;
wherein said setting means comprises a rocker pivotable about an
axis and having a first arm connected to said cleaning member and a
second arm running parallel with said axis and connected rotatably
and slidingly to a fork fixed to said ink collecting means.
9. A printer as claimed in claim 8, including means for selectively
engaging with said first print head and with said second print head
when it moves to said nozzle restoring, protecting and cleaning
device to selectively couple said ink collecting means to said
first print head and to said second print head.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a service station for an ink jet
printer.
U.S. Pat. No. 5,155,497 (Martin et al.) discloses a service station
which includes a cleaning member which removes residues of ink from
the print head, and also includes means for isolating the head from
the external environment to maintain it in an efficient condition.
The service station uses a support that can be rotated selectively
through 180.degree.. This support carries on one side a first
cleaning blade and a first elastic cover, and on the opposite side
a second blade and a second elastic cover. Depending on what type
of head the printer is using, i.e. either a head for printing in
black or a head for printing in colors, the support is rotated as
required in order selectively to couple the first blade and cover
or the second blade and cover, to one or the other head.
This service station is therefore of complex construction in view
of the large number of component parts, and is very space-hungry,
especially if it is to be fitted to a small printer.
SUMMARY OF THE INVENTION
An object of the present invention is therefore to provide a
service station of simple construction that takes up relatively
little space.
The invention is defined in the independent claims below, to which
reference should now be made. Advantageous features of the
invention are set forth in the appendant claims.
A preferred embodiment is described in more detail below, in which
an ink jet printer has a station for cleaning, restoring and
protecting the nozzles of the print head. A cleaning blade is
coupled to the nozzle restoring and protecting device and is
controlled by it when moved, by the motion of the print head, into
its operating position. The restoring and protecting device
comprises two covers, or caps, that can be selectively coupled to
one or the other of two heads for printing in black or in color
respectively. The restoring and protecting device sets the cleaning
blade in the best position for cleaning the two heads, by means of
a rocker. The preferred service station is of relatively simple
construction and uses only a small number of component parts.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail, by way of example,
with reference to the accompanying drawings, in which:
FIG. 1 diagrammatically shows an ink jet printer comprising a
service station embodying the invention;
FIG. 2 shows a front view of the service station at rest;
FIG. 3 shows the service station of FIG. 2 in operation;
FIGS. 4 to 6 show on an enlarged scale front, side, and plan views
respectively of a support of the service station shown in FIG.
2;
FIG. 7 shows a view of a slide part mounted on the support shown in
FIG. 5;
FIG. 8 is a lateral view of the slide part shown in FIG. 7;
FIG. 9 is a view of a rocker which operates the support shown in
FIG. 4; and
FIG. 10 is an end view of the rocker shown in FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The Figures illustrate a service station for a printer having an
ink jet print head that moves over a printing support and comprises
a cleaning member which removes residues of ink from the head, and
capping means which isolate this head from the external environment
and maintain it in an efficient condition.
With reference to FIG. 1, the numeral 10 indicates a printer having
a frame 12 on which a carriage 14 runs backwards and forwards,
guided and supported by two guides 16. The carriage 14 carries a
support 18 designed to hold a module 20 for printing in black, but
which is interchangeable alternatively with a similar module for
color printing.
The module 20 consists of an ink jet print head 22 integral with
its own ink reservoir 21.
The module 20 may alternatively be composed of an intermediate
support that fits inside the support 18 and carries a print head,
and accommodates in turn a removable ink cartridge which connects
hydraulically with the head so as to feed it.
The head 22 carries a plate 24 in which nozzles 26 are formed (FIG.
2), from which drops of ink are expelled towards a printing support
28 (FIG. 1) travelling over the frame 12 in the direction 29.
The printer 12 includes a service station 30 for the print head 22.
It is positioned on the path of this head, at one end of its travel
in a service point 32. The service station 30 comprises a cleaning
part 34, and a device 40 for restoring and protecting the nozzles
26. The cleaning part 34 is in the shape of a flexible blade
mounted vertically on a trough 36 for collecting the ink removed by
the blade 34.
The trough 36 is hinged to the frame 12 by means of a pin 31, on
which the trough 36 can pivot as indicated by the arrow 33. The
trough is biased upwardly or in an anti-clockwise direction as seen
in FIG. 2 by a spring 97, indicated diagrammatically. The blade 34
projects above the trough 36 and is positioned perpendicularly to
the path of the head 22. The blade 34 is of a height such that when
the trough 36 is in the rest position, shown in FIGS. 1 and 2, the
top edge 38 of the blade 34 interferes either with the head 22 for
printing in black, or with a head 23 (FIG. 2) for color
printing.
The device 40 for restoring and protecting the nozzles 26 is
positioned beyond and in line with the trough 36, in the direction
of motion of the carriage 14 towards the position 32. The device 40
comprises a support 42 (FIGS. 4 to 6) capable of independently
pivoting and translating axially on a shaft 44 fixed to the frame
12, in the directions of the arrows 45 and 47 respectively (FIG.
1). There are minor differences in the shapes of certain parts
shown in the drawings, most notably between FIG. 1 and the other
Figures, which illustrates that the device may be made in many
different forms embodying the invention.
The support 42 (FIG. 5) includes two arms 53 and 55 parallel with
each other and each integral at one end with a cross member 57,
while another end 59 of each arm is provided with a hole 60
containing the shaft 44.
Mounted on the support 42 is a part 46 for collecting the ink
purged from the nozzles 26. It consists of a slide 48 (FIG. 7)
surmounted by a cap or cover 50 of soft rubber to protect the
nozzles. The slide 48 is formed by a body 52 of approximately
parallelepidal shape that travels between the arms 53 and 55 of the
support 42. An upper portion 62 of the body 52 projects above the
support 42 through an aperture 63 (FIG. 6) in the cross member 57.
A hole 66 containing the shaft 44 passes through the opposite lower
portion 64 of the body 52.
The upper portion 62 comprises two recesses 68 and 69 side by side
and elongate in the direction of the arrow 47, that is
perpendicularly to the path of the heads 22 and 23; these recesses
are designed to hold the black ink and the colored ink
respectively, as will be explained below. The recess 69 for the
colored ink is longer than the recess 68 for the black ink because
the color head 23 has a greater transverse dimension than the black
head 22.
The recess 69 for the colored ink is closed on the underside, while
the recess 68 for the black ink is connected by a tube 67 (FIGS. 1,
2) to a suction device, not shown in the drawings, for aspirating a
certain amount of ink from the nozzles of the head 22 in order to
avoid possible coagulation of the black ink, which is more likely
to coagulate than the colored ink, given its composition.
The cap or cover 50 is fixed elastically to the upper portion 62 of
the body 52 and is provided with two apertures 70 and 71 over the
recesses 68 and 69 respectively. The apertures 70 and 71 are
surrounded by corresponding projecting and elastically yielding
edges 73 designed to conform perfectly with the lower face 25 of
the head 22, or alternatively of the head 23, when moved into the
service point 32.
As has already been indicated earlier, the support 42 and the unit
46 can travel axially along the shaft 44 as a result of a manual
action by the operator, from a first position in which the recess
68 and the corresponding aperture 70 in the cap or cover 50 are
situated in the path of the head 22 for the black ink, to a second
position in which the recess 69 and the corresponding aperture 71
in the cap or cover 50 are situated in the same path when the color
head is mounted on the carriage 14.
The printer in fact generates a signal for the operator indicating
whether the black head or color head is mounted on the carriage
14.
The positioning of the support 42 in each of the two positions is
made stable by means of a compression spring 75 housed inside the
body 52 (FIG. 7), and a ball 74 engaging selectively with two
grooves 65 on the shaft 44. Movement from one position to the other
is brought about by means of a rod 77 (FIG. 1) operated by the
operator.
The support 42 (FIG. 2) is connected to the trough 36 by means of a
rocker 80 hinged to the frame 12 by pins 81 and having a first arm
82 coupled slidingly with a fork 84 integral with the support 42. A
second arm 86 of the rocker 80, situated about 180.degree. away
from the first arm 82, pivots in a corresponding fork 85 on the
trough 36.
The first arm 82 runs approximately parallel with the longitudinal
axis "A" of the rocker 80 in such a way that its edge 83, which
forms a guide for the fork 84, is always engaged in the fork as the
support 42 is moved in the direction of the arrow 47 (FIG. 1).
If the color head 23 is situated at a level "C" higher than a level
"N" of the black head 22, by a predetermined distance "D", as shown
in FIG. 2, for example between 0.4 mm and 0.6 mm, it is necessary,
in order to ensure correct cleaning action of the blade 34 on both
heads, that the top edge 38 of the blade 34 is pressed against both
heads with the same force. This is achieved by keeping the
interference between the edge 38 of the blade 34 and each of the
heads constant.
For this purpose the guide 83 of the rocker 80 (FIG. 9) is inclined
by an angle "alpha" (.alpha.) of between approximately 3.degree.
and 6.degree. with respect to the axis "A" of the rocker 80. In a
preferred embodiment, the guide 83 is subdivided into three
portions 87, 88, 89. The endmost portions 87 and 89 run parallel
with the axis "A", while the central portion 88, connected
continuously with the portions 87 and 89, is inclined at the angle
"alpha". In this way the axial movement of the support 42 on the
shaft 44 causes a rotation of the rocker 80 and consequently of the
trough 36, so that the blade 34 is raised or lowered relative to
the levels "C" or "N" of the corresponding heads, thus always being
in the best position for the cleaning action.
The rocker 80 with the inclined guide 83 therefore forms a blade
setting part, controlled by the axial position assumed by the
support 42.
The angle "alpha" can clearly assume values other than those
indicated above depending upon the difference between the levels
"C" and "N" and upon the dimensions of the components used in
embodiments differing from the preferred embodiment described
here.
After a certain number of printed lines, the carriage 14 is brought
automatically by the printer's logic unit to the service point 32,
where, at the end of its travel, a trigger member formed by a tooth
90 on the carriage 14 (FIGS. 1 and 2) moves a lever 91 which is
coupled slidingly to a rib 94 on the support 42, causing said
support to turn in the direction of the arrow 45. The lever 91 is
prevented from moving transversely, but not from pivoting, by a
slot 96 in the frame 12.
FIG. 3 shows the position adopted by the support 42 and by the
trough 36 as a result of the action of the tooth 90. As it rotates,
the cap 50 presses against, without sliding over, the lower surface
25 of whichever head is fitted at that time. The cap or cover 50 is
held against the surface 25 by the action of the spring 75 (FIG. 7)
which allows the slide part 48 to make small movements relative to
the support 42, owing to the elongated shape in section of the hole
66. In particular, the spring 75 allows the part 48 to adapt to
different levels "C" and "N" of different heads.
The clockwise rotation (FIG. 2) of the support 42 about the shaft
44 causes, by means of the rocker 80, a clockwise rotation of the
trough 36 and a consequent lowering of the blade 34 (FIG. 3), which
moves away from the surface 25 of the heads after having removed
any trace of ink from the surface 25.
When the color head 23 is kept in the service point 32, the nozzles
are isolated from the external environment, in an atmosphere where
the humidity is such that, owing to the low tendency of colored
inks to coagulate, they remain efficient for a suitable period of
time.
Since in the case of a head 22 with black ink, this ink would tend
to coagulate in the nozzles when the nozzles are inactive, a
certain amount of ink is aspirated from the nozzles and collected
in the recess 68.
When the color head or the black head is moved away from the
service point, the tooth 90 releases the lever 91. Owing to the
action of the spring 97 (FIG. 2), the trough 36 rotates
anticlockwise, causing the blade 34 to slide again over the surface
25 of the print heads, to again remove any traces of ink, before
printing is recommenced.
It will be understood that the service station for an ink jet
printer embodying the invention may be modified or have parts added
to it without departing from the scope of the invention. For
example, the print head may be a fixed line-type head and the unit
formed by the cleaning part and restoring device may be mounted on
a carriage that moves along the head.
* * * * *